brittle

Etymology

From Middle English britel, brutel, brotel (“brittle”), from Old English *brytel, *bryttol (“brittle, fragile”, literally “prone to or tending to break”); equivalent to brit + -le.

adj

1. Inflexible; liable to break, snap, or shatter easily under stress, pressure, or impact.
   Cast iron is much more brittle than forged iron.
   A diamond is hard but brittle.
   'Do you suppose our convent, and I too, / Are insufficient, then, to pray for you? / Thomas, that joke's not good. Your faith is brittle. 1951, Geoffrey Chaucer, translated by Nevill Coghill, The Canterbury Tales: Translated into Modern English (Penguin Classics), Penguin Books, published 1977, page 329
2. Not physically tough or tenacious; apt to break or crumble when bending.
   Shortbread is my favorite cold pastry, yet being so brittle it crumbles easily, and a lot goes to waste.
3. (archaeology) Said of rocks and minerals with a conchoidal fracture; capable of being knapped or flaked.
4. Emotionally fragile, easily offended.
   What a brittle personality! A little misunderstanding and he's an emotional wreck.
5. (engineering, computing, of a system) Poorly error- or fault-tolerant; having little in the way of redundancy or defense in depth; susceptible to catastrophic failure in the event of a relatively-minor malfunction or deviance.
6. (informal, proscribed) Diabetes that is characterized by dramatic swings in blood sugar level.

noun

1. A confection of caramelized sugar and nuts.
   As a child, my favorite candy was peanut brittle.
2. (by extension) Anything resembling this confection, such as flapjack, a cereal bar, etc.

verb

1. (intransitive) To become brittle.
   The project is based on a similar project, the Class project, which was started by the University of Cornell several years ago under the leadership of Stuart Lynn to preserve brittling old books. 1999, J. Siekmann, Maria T. Pazienza, J. G. Carbonell, Information Extraction: Towards Scalable, Adaptable Systems, page 24
   Her heart fluttered, then stilled when May snapped the image away and her voice brittled. 2020, Alys Murray, The Magnolia Sisters